48 research outputs found

    Spatial and Sex-Specific Variation in Growth of Albacore Tuna (Thunnus alalunga) across the South Pacific Ocean

    Get PDF
    Spatial variation in growth is a common feature of demersal fish populations which often exist as discrete adult sub-populations linked by a pelagic larval stage. However, it remains unclear whether variation in growth occurs at similar spatial scales for populations of highly migratory pelagic species, such as tuna. We examined spatial variation in growth of albacore Thunnus alalunga across 90° of longitude in the South Pacific Ocean from the east coast of Australia to the Pitcairn Islands. Using length-at-age data from a validated ageing method we found evidence for significant variation in length-at-age and growth parameters (L∞ and k) between sexes and across longitudes. Growth trajectories were similar between sexes up until four years of age, after which the length-at-age for males was, on average, greater than that for females. Males reached an average maximum size more than 8 cm larger than females. Length-at-age and growth parameters were consistently greater at more easterly longitudes than at westerly longitudes for both females and males. Our results provide strong evidence that finer spatial structure exists within the South Pacific albacore stock and raises the question of whether the scale of their “highly migratory” nature should be re-assessed. Future stock assessment models for South Pacific albacore should consider sex-specific growth curves and spatial variation in growth within the stock

    Experimental evidence for sustained carbon sequestration in fire-managed, peat moorlands.

    Get PDF
    Peat moorlands are important habitats in the boreal region, where they store approximately 30% of the global soil carbon (C). Prescribed burning on peat is a very contentious management strategy, widely linked with loss of carbon. Here, we quantify the effects of prescribed burning for lightly managed boreal moorlands and show that the impacts on peat and C accumulation rates are not as bad as is widely thought. We used stratigraphical techniques within a unique replicated ecological experiment with known burn frequencies to quantify peat and C accumulation rates (0, 1, 3 and 6 managed burns since around 1923). Accumulation rates were typical of moorlands elsewhere, and were reduced significantly only in the 6-burn treatment. However, impacts intensified gradually with burn frequency; each additional burn reduced the accumulation rates by 4.9 g m−2 yr−1 (peat) and 1.9 g C cm−2 yr−1, but did not prevent accumulation. Species diversity and the abundance of peat-forming species also increased with burn frequency. Our data challenge widely held perceptions that a move to 0 burning is essential for peat growth, and show that appropriate prescribed burning can both mitigate wildfire risk in a warmer world and produce relatively fast peat growth and sustained C sequestration

    Longitudinal expression profiling identifies a poor risk subset of patients with ABC-type Diffuse Large B Cell Lymphoma

    Get PDF
    Despite the effectiveness of immuno-chemotherapy, 40\cell lymphoma (DLBCL) experience relapse or refractory disease. Longitudinal studies have previously focused on the mutational landscape of relapse but fell short of providing a consistent relapse-specific genetic signature. In our study, we have focussed attention on the changes in gene expression profile accompanying DLBCL relapse using archival paired diagnostic/relapse specimens from 38 de novo DLBCL patients. Cell of origin remained stable from diagnosis to relapse in 80\ with only a single patient showing COO switching from ABC to GCB. Analysis of the transcriptomic changes that occur following relapse suggest ABC and GCB relapses are mediated via different mechanisms. We developed a 30-gene discriminator for ABC-DLBCLs derived from relapse-associated genes, that defined clinically distinct high and low risk subgroups in ABC-DLBCLs at diagnosis in datasets comprising both population-based and clinical trial cohorts. This signature also identified a population of \lt;60-year-old patients with superior PFS and OS treated with Ibrutinib-R-CHOP as part of the PHOENIX trial. Altogether this new signature adds to the existing toolkit of putative genetic predictors now available in DLBCL that can be readily assessed as part of prospective clinical trials

    Salient Elements in Novice Solutions to Code Writing Problems

    No full text
    This paper presents an approach to the evaluation of novice programmers' solutions to code writing problems. The first step was the development a framework comprised of the salient elements, or programming constructs, used in a set of student solutions to three typical code writing assessment problems. This framework was then refined to provide a code quality factor framework that was compared with an analysis using the SOLO taxonomy. We found that combining our framework with the SOLO taxonomy helped to define the SOLO categories and provided an improved approach to applying the principles of SOLO to code writing problems

    Report on the final BRACElet workshop: Auckland University of Technology, September 2010

    No full text
    This paper reports on the thirteenth and final BRACElet workshop. In this paper we provide a brief retrospective review of the workshops and the findings that have resulted from this multi-institutional multinational investigation into the teaching and learning of novice programmers. Subsequently we report on the work undertaken during the final workshop and then discuss future avenues for research that have evolved as a result of the BRACElet project

    Report on the Final BRACElet Workshop: Auckland University of Technology, September 2010

    No full text
    This paper reports on the thirteenth and final BRACElet workshop. In this paper we provide a brief retrospective review of the workshops and the findings that have resulted from this multi-institutional multinational investigation into the teaching and learning of novice programmers. Subsequently we report on the work undertaken during the final workshop and then discuss future avenues for research that have evolved as a result of the BRACElet project

    An Australasian study of reading and comprehension skills in novice programmers, using the bloom and SOLO taxonomies

    Full text link
    In this paper we report on a multi-institutional investigation into the reading and comprehension skills of novice programmers. This work extends previous studies (Lister 2004, McCracken 2001) by developing a question set within two key pedagogical frameworks: the Bloom and SOLO taxonomies. From this framework of analysis some interesting emergent patterns relating the cognitive level of the questions to student performance have been identified. © 2006, Australian Computer Society, Inc
    corecore